In comparison, in January 2011, 89 women gave birth under "emergency" circumstances, according to the Hong Kong Hospital Authority.

In total, babies born to mainland mothers in Hong Kong totalled 32,000 in 2010, accounting for about 40 per cent of all births.

The influx of pregnant Chinese mothers – who by giving birth claim automatic rights for themselves and their newborns – is the main source of the rising resentment among Hong Kongers towards their compatriot neighbours.

The Hong Kong administration announced last month it is to limit the number of the so-called birth tourists, setting a quota of 3,400 births for non-local women per year, down from 10,000 last year.

But mainlanders are flouting the rules by arriving at emergency wards in the late stages of labour.

As well as better medical treatment, newborns receive automatic residency and are entitled to 12 years free education.

The unwanted baby boom is putting a strain on resources as well as causing public anger.

A recent media advert in a Hong Kong newspaper described mainlanders as "locusts", sparking outrage among Chinese.

Earlier this week, Chinese family planning officials warned mainland parents they remain subjected to China's one-child policy if they give birth to a second child in Hong Kong and face punishment if they flout the rules.

Tighter boarder controls have also been implemented to weed out pregnant women at immigration.

But labour wards continue to assist mainlanders, most of whom pay agents in China to take them across the border to stay in illegal shelters in Hong Kong while they wait to go into labour.

"As long as Hong Kong provides better medical care or more benefits for pregnant mainland women, it is impossible for the Hong Kong administration to completely eradicate the problem," said professor Feng Yujun from the Renmin University in Beijing.